“If Cory Booker is elected, California will have a third senator, because Booker will be beholden to the Silicon Valley billionaires who funded his ‘start-up’ business,” said Republican Senate candidate Steve Lonegan in a statement Thursday. “Additionally, campaign donations were being raised at the same time as funding for Cory Booker’s business. This is sketchy, to say the least.”

Silicon Valley has backed Booker’s recent campaigns – the Times reports that tech executives and employees provided more than $400,000 for his 2010 mayoral campaign and nearly $700,000 for his Senate run.

“As [Newark Mayor Cory Booker] has said himself, running the city takes a lot of time, yet it seems that the mayor must have spent an enormous amount of time getting his startup off the ground and courting financial backers,” said Democratic Senate candidate Frank Pallone’s campaign. “This comes weeks after the mayor amended his financial disclosure forms to detail additional income related to his startup tech company, and the fact that at least one independent ethics group is taking him to task for his business relationships is a cause for alarm.”

Booker has a financial stake worth somewhere between $1 and $5 million in Waywire, according to recently updated disclosure forms. His other assets are cumulatively valued at no more than $730,000. The Times reports that Booker has the largest stake of the firm’s three co-founders, even though he is not involved in its day-to-day operations. He did take a significant role in obtaining financing, and some of Waywire’s investors have also donated to Booker’s Senate campaign.

“If you’re getting a large percentage just because you’re a well-known political figure, that’s a little bit problematic,” said Melanie Sloan, executive director of Citizens for Responsibility and Ethics in Washington, told the Times. “People tend to prefer their political figures not to be cashing in on their positions of public trust.”

If Booker is elected to the U.S. Senate, its rules would prevent him from accepting speaking fees which made the mayor $1.3 million over five years. (Booker’s campaign says much of that money was donated to charities.) He would likely also have to step down from Waywire’s board, ethics experts say, but he would be able to retain his financial interest. Whether that retains will be a growing source of wealth remains to be seen.

On Friday, the New York Post reported that employees of the company are seeking new jobs because they expect Waywire to fold shortly after the special election to fill the remainder of the late U.S. Sen. Frank Lautenberg’s term in October.

Eight employees were laid off earlier this year and the company closed its offices in Manhattan when Waywire shifted its focus away from original content creation to concentrate on video curation, according to the Times report. The company’s remaining employees, some of whom are also working in other unrelated ventures, now work “virtually.”

On Tuesday, voters will choose their party’s nominee to run in October’s special election for U.S. Senate. Booker, Pallone, U.S. Rep. Rush Holt and Assembly Speaker Sheila Oliver are running in the Democratic primary; Lonegan and Dr. Alieta Eck are running in the Republican primary.